RFR Backport: 8078024: javac, several incorporation steps are silently failing when an error should be reported

[Peter Zhelezniakov]

Hi all,

Can I get a review on this one please? This is backport of a fix made for JDK9. The src/ part of the original patch applies cleanly, in the test/ part some contextual changes were necessary. I've also updated a copyright.
Bug: https://bugs.openjdk.java.net/browse/JDK-8078024
Webrev: http://cr.openjdk.java.net/~alexsch/peterz/8078024
This fix improves compilation situation for one of our clients while their project compiles with JDK11 but fails to compile with JDK8.
Thanks!